Chaoran Xu
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4 records found
1
Tropical cyclones (TCs) significantly influence coastal sedimentation, geomorphologic features, and morphodynamic processes through strong winds, heavy rains, and storm surges. These effects are particularly pronounced in the east China coastal ocean. However, the impacts of poleward and landward shifts in TC tracks on sedimentology, specifically sediment transport and erosion-deposition processes, remain insufficiently understood. This study utilizes the Delft3D-FM numerical model integrated with TC best track data and field measurements to investigate sediment transport patterns under historical TC tracks and to quantify erosion responses to poleward and landward track shifts. From the historical sediment transport pattern derived from the typical historical TC track, results reveal that sediment in waters shallower than 30 m is highly sensitive to TC activity, with four distinct zones where net sediment transport is sensitive to the change of typical historical TC tracks. Coastal erosion depth changes due to poleward and landward shifts of typical TC tracks during the peak TC intensity period are quantified as 0.24–1.63 cm°N−1 and 0.05–1.06 cm°E−1, respectively. Under global warming scenarios, these values are projected to increase by 2.45%–8.00% and 4.71%–13.33%, respectively. Identifying the coastal areas more susceptible to TC-induced sediment transport and quantitatively assessing the effects of poleward and landward track shifts are important for understanding local TC variability and supporting research on sedimentology during TCs and the future protection of coastal areas.
Analyzing the spatial-temporal changes in tropical cyclone (TC) tracks in the east China coastal ocean (ECCO) to quantify the magnitude of poleward and landward migration of TCs is of significant importance for coastal disaster mitigation and planning due to its susceptibility to the impacts of TCs. In this study, the TCs that affected the ECCO from 1949 to 2022 are classified into three typical types of tracks using the k-means clustering method, mass moments, and track interpolation based on TC location, shape, and intensity information. Type 1 is a northwestward track, Type 2 is a northwest to northeast-turning track, and Type 3 is a northwest to northeast-turning offshore track. Type 1 tracks mainly make landfall in southern China, while Type 2 predominantly makes landfall in eastern China. Moreover, the proportion of Type 1 decreases while their landfall percentage increases over time, and the proportion of Type 2 tracks is increasing. The probability of TC effects on the eastern and northern parts of the ECCO is increasing, and the boundary where the TC center reaches after landfall is shifting landward. During the period from 1994 to 2022, there has been a significant migration in TC tracks, with the mean centroid of the TCs affecting the ECCO shifting westward by 0.66° in longitude and northward by 1.26° in latitude, which means the magnitude of the poleward shift is about twice that of the landward shift. This migration appears to have been pre-conditioned by a combined influence of a weakening westward steering flow, reduced vertical wind shear, and warmer sea surface temperature Our findings provide valuable insights into the longitudinal and latitudinal migration of TC tracks and have important implications for disaster prevention, mitigation planning, and the adjustment of crucial coastal protection zones in the ECCO and similar regions around the globe.
Hurricane Ike, which struck the United States in September 2008, was the ninth most expensive hurricane in terms of damages. It caused nearly USD 30 billion in damage after making landfall on the Bolivar Peninsula, Texas. We used the Delft3d-FM/SWAN hydrodynamic and spectral wave model to simulate the storm surge inundation around Galveston Bay during Hurricane Ike. Damage curves were established through the relationship between eight hydrodynamic parameters (water depth, flow velocity, unit discharge, flow momentum flux, significant wave height, wave energy flux, total water depth (flow depth plus wave height), and total (flow plus wave) force) simulated by the model and National Flood Insurance Program (NFIP) insurance damage data. The NFIP insurance database contains a large amount of building damage data, building stories, and elevation, as well as other information from the Ike event. We found that the damage curves are sensitive to the model grid resolution, building elevation, and the number of stories. We also found that the resulting damage functions are steeper than those developed for residential structures in many other locations.